How iced tea can lead to kidney failure

Although the health benefits of tea are roundly lauded, an Arkansas man recently found out that too much can be devastating.

Few things seem as salubrious as tea. And in fact, many use it as a natural remedy for all that ails. It is enthusiastic with antioxidants, it helps fight illness, it hydrates, it soothes – it performs many feats of healthy derring-do. But alas, tea has its limits; or to be more precise, we have our limits when it comes to consuming it.

This is the lesson learned by a 56-year old Arkansas resident who went to the hospital suffering from nausea, weakness, fatigue and body aches. Doctors determined that his kidneys were badly clogged and inflamed by the food chemical known as oxalate, reports The Washington Post. The unidentified man remains on dialysis, and may be for the duration of his life, says Dr. Umbar Ghaffar of the University of Arkansas for Medical Sciences in Little Rock.

After ruling out several possible causes for the man's kidney failure, doctors stumbled upon what they now believe was the reason: His conspicuous consumption of iced tea, a whopping 16 eight-ounce cups a day.

“It was the only reasonable explanation,” says Ghaffar.

Oxalate is a compound that occurs naturally in foods, including black tea; beets, spinach, rhubarb, strawberries, nuts, chocolate, tea, wheat bran, and beans are also notably high. These foods are known to increase oxalate in the urine and kidney stone formation; and in rare cases, can lead to renal failure.

Black tea is one of the richest sources of oxalate, containing 50 to 100 mg per 100 ml, a level that is similar to or higher than that in many foods considered to be rich in oxalate, report the doctors who wrote about the case in the New England Journal of Medicine. Given the amount of tea he was drinking, the patient's daily consumption of oxalate was above than 1500 mg – more than three to 10 times than the average American consumes daily.

But should you stop drinking tea? No. It’s still a good choice, in moderation; this case appears to be unusual, notes Dr. Randy Luciano, a Yale School of Medicine kidney specialist who has worked with oxalate-induced kidney damage before.

“I wouldn’t tell people to stop drinking tea,” said Luciano, who was not involved in the research. What the man drank was excessive, "a lot of tea.”